The mission of the Northwestern University IMSD (NU IMSD) is to contribute to the diversification of the biomedical research workforce by providing a carefully designed professional development sequence that enhances early PhD training. The program has an equal focus on developing the talents of students who enter the PhD with high levels of preparation, and those who come from lower-resourced backgrounds but who display key characteristics that predict success. This renewal builds upon 8 years of progressive success and a program design that pays careful attention to the rapid transitions and growth that takes place during the first 2 years of the PhD. The NU IMSD is truly unique in its foundation on multiple social science theories and models that explain the extra challenges faced by underrepresented minority individuals. These social science theories and their application to program design have arisen from large empirical and applied research studies of career progression and decision-making of young scientists that are being conducted alongside the NU IMSD. Those studies and our ongoing program evaluation efforts have led to the design of a sequence of activities that facilitate: 1. Rapid and successful transitions into PhD training;2. Understanding and succeeding in laboratories that includes both visible and invisible expectations; 3. Choosing a research mentor and group that align with scientific, mentoring and social preferences; 4. Rapid development of oral communication skills given their strong contributions to external and internal perceptions of competence; 5. Understanding of key principles of effective mentoring relationships, enabling students to guide their own mentoring (mentoring up) rather than passively depend on actions of mentors; 6. Development of high level scientific writing skills through a unique, highly successful deconstruction of NIH-style proposal writing into easily understood and modeled rhetorical patterns; 7. Active exploration of career options early in training to minimize conscious or unconscious ambivalence of purpose or confusion throughout the PhD training. The NU IMSD also provides the foundation for a larger program open to all beginning biomedical PhD students, called the Collaborative Learning and Integrated Mentoring in the Biosciences (CLIMB) program. By being part of CLIMB, IMSD students are not subject to risks of stereotyping associated with minority-only programs, and enjoy a much larger interdisciplinary cohort of young scientists to get to know within the context of guided professional development. Being situated within CLIMB also enables the IMSD to play a major role in institutional diversity efforts, complementing the visible and energetic diversity initiatives of the life science faculty, the NU Graduate School and its Dean.